The patterns on the cliff were formed by the effects of flowing lava thousands of years ago.

Dazhu Mountain, or Big Bead Mountain, is located in Jiaonan city on Shandong Peninsula. On one side of the mountain, there is a black rock cliff 20 meters high to which are attached numerous "rock eggs" of various sizes. From time to time, some of these rock eggs are heard falling down by nearby villagers.

Recently, this reporter paid a visit to Big Bead Mountain to witness this bizarre cliff, which has become famous in the surrounding areas.

At the foot of the cliff there are piles of dark round rocks, some oval-shaped, some cuboids. Larger ones have diameters of up to 0.6 meters, while the smaller ones resemble eggs. The surface of the rocks is rough and uneven, with dents from small air bubbles, reflecting sunlight in some places. The egg-shaped rocks are slightly heavier than normal stones.

Some geologists say the rocks are made of basalt or andesite forced onto the earth’s surface with granite during the orogenetic process. Exposed to all kinds of weather conditions, comparatively soft parts of the rocks gradually break and peel off, leaving the hard stone cores on the cliff, thus forming the "rock eggs".

Near the cliff, this reporter met a villager surnamed Zhang. "Here there used to be a stone pit, but it was abandoned many years ago, since no one made any use of these black stone eggs. I always remind those who try to climb the cliff to watch out for falling rocks. The rock eggs fall down more frequently in the dry seasons, like autumn and early spring. During thunderstorms, even more of them break apart from the cliff. So many people will come and pick some stone eggs they find funny," said Zhang.

The round rocks became brittle under the effects of wind abrasion.

Piles of "eggs" hanging from the cliff

A villager tells this reporter that each year many rock eggs fall to the ground.

By Audrey and Chen Zhilin